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author | Peter Maydell | 2016-07-01 12:18:00 +0200 |
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committer | Peter Maydell | 2016-07-01 12:18:01 +0200 |
commit | 1fb4c13e4f92bda047f30177d5b8c2b4ca42e8b8 (patch) | |
tree | 1a364b8593876135e3490a850d687569b79aa772 /util/range.c | |
parent | linux-user: Fix compilation when F_SETPIPE_SZ isn't defined (diff) | |
parent | qapi: Fix memleak in string visitors on int lists (diff) | |
download | qemu-1fb4c13e4f92bda047f30177d5b8c2b4ca42e8b8.tar.gz qemu-1fb4c13e4f92bda047f30177d5b8c2b4ca42e8b8.tar.xz qemu-1fb4c13e4f92bda047f30177d5b8c2b4ca42e8b8.zip |
Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-06-30' into staging
QAPI patches 2016-06-30
# gpg: Signature made Thu 30 Jun 2016 14:29:43 BST
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653
* remotes/armbru/tags/pull-qapi-2016-06-30:
qapi: Fix memleak in string visitors on int lists
qapi: Simplify use of range.h
range: Create range.c for code that should not be inline
qapi: Fix crash on missing alternate member of QAPI struct
checkpatch: There is no qemu_strtod()
qobject: Correct JSON lexer grammar comments
json-streamer: Don't leak tokens on incomplete parse
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'util/range.c')
-rw-r--r-- | util/range.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/util/range.c b/util/range.c new file mode 100644 index 0000000000..e90c988dbf --- /dev/null +++ b/util/range.c @@ -0,0 +1,76 @@ +/* + * QEMU 64-bit address ranges + * + * Copyright (c) 2015-2016 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + * + */ + +#include "qemu/osdep.h" +#include "qemu/range.h" + +/* + * Operations on 64 bit address ranges. + * Notes: + * - ranges must not wrap around 0, but can include the last byte ~0x0LL. + * - this can not represent a full 0 to ~0x0LL range. + */ + +/* Return -1 if @a < @b, 1 if greater, and 0 if they touch or overlap. */ +static inline int range_compare(Range *a, Range *b) +{ + /* Zero a->end is 2**64, and therefore not less than any b->begin */ + if (a->end && a->end < b->begin) { + return -1; + } + if (b->end && a->begin > b->end) { + return 1; + } + return 0; +} + +/* Insert @data into @list of ranges; caller no longer owns @data */ +GList *range_list_insert(GList *list, Range *data) +{ + GList *l; + + /* Range lists require no empty ranges */ + assert(data->begin < data->end || (data->begin && !data->end)); + + /* Skip all list elements strictly less than data */ + for (l = list; l && range_compare(l->data, data) < 0; l = l->next) { + } + + if (!l || range_compare(l->data, data) > 0) { + /* Rest of the list (if any) is strictly greater than @data */ + return g_list_insert_before(list, l, data); + } + + /* Current list element overlaps @data, merge the two */ + range_extend(l->data, data); + g_free(data); + + /* Merge any subsequent list elements that now also overlap */ + while (l->next && range_compare(l->data, l->next->data) == 0) { + GList *new_l; + + range_extend(l->data, l->next->data); + g_free(l->next->data); + new_l = g_list_delete_link(list, l->next); + assert(new_l == list); + } + + return list; +} |